~ruther/qmk_firmware

1acafc94f40154db009d5ed55bca204c2399c0a8 — yiancar 5 years ago 2ce6adf 
Correct ARM STM32 I2C frequency. (#7080)

It was beleaved that this setting result in a 400Khz I2C bus.

This was incorrect, actual frequency measure with a logic analyzer was around 150Khz.

This is derived from the excel sheet linked in the .h file.
Also confirmed with the ST IDE.
patch browse .tar.gz 
1 files changed, 5 insertions(+), 5 deletions(-)

M drivers/arm/i2c_master.h

M drivers/arm/i2c_master.h => drivers/arm/i2c_master.h +5 -5
@@ 73,19 73,19 @@
// The default timing values below configures the I2C clock to 400khz assuming a 72Mhz clock
// For more info : https://www.st.com/en/embedded-software/stsw-stm32126.html
#    ifndef I2C1_TIMINGR_PRESC
#        define I2C1_TIMINGR_PRESC 15U
#        define I2C1_TIMINGR_PRESC 0U
#    endif
#    ifndef I2C1_TIMINGR_SCLDEL
#        define I2C1_TIMINGR_SCLDEL 4U
#        define I2C1_TIMINGR_SCLDEL 7U
#    endif
#    ifndef I2C1_TIMINGR_SDADEL
#        define I2C1_TIMINGR_SDADEL 2U
#        define I2C1_TIMINGR_SDADEL 0U
#    endif
#    ifndef I2C1_TIMINGR_SCLH
#        define I2C1_TIMINGR_SCLH 15U
#        define I2C1_TIMINGR_SCLH 38U
#    endif
#    ifndef I2C1_TIMINGR_SCLL
#        define I2C1_TIMINGR_SCLL 21U
#        define I2C1_TIMINGR_SCLL 129U
#    endif
#endif